1. Field of the Invention
The present invention relates to a muffler system for refrigeration motor-compressors and more precisely to suction muffler.
2. Description of the Prior Art
As it is well known, when the compressor is assembled, it is installed in the refrigerator and hermetically connected to the refrigeration circuit. Such a hermetic connection does not allow any maintenance within the refrigeration circuit components, thus it is important that no working or soldering residues remain within the system, risking damage to the most important components, such as for example the valve plate-piston unit where the refrigerant gas is sucked and then pumped at determined pressure into the refrigeration circuit. The compressor components, before being assembled, are accurately washed in order to remove any alien particles therefrom. This operation may not be effected in the portion of the circuit placed in the refrigerator, which is composed of a condenser and an evaporator, because it is too difficult and expensive. Compressors are known where a filter is inserted in the suction muffler in order to avoid the alien particles from reaching the valve plate-piston unit.
In such a way, the particles are stopped by the filter which may partially or completely clog and since it is impossible to replace the filter, a smaller quantity of gas is sucked into the compression chamber. This is due to the fact that the gas warms before entering the compressor chamber and thus its volume increases. As a consequence, there is a smaller discharge of compressed gas in the circuit and thus a lower efficiency of the refrigerator.
In other compressors, on the muffler, near the entry hole, a little plate is positioned perpendicularly to the refrigerant gas entry direction. Any particles suspended in the gas, strike against the little plate and, precipitate in the compressor bottom while the gas passes into the muffler through the hole near said little plate. By this solution the particles which strike the little plate, rebound, and enter the muffler hole and thus reach the valve plate-piston unit, to damage it. Another drawback of this solution is due to the fact that the little plate, as it is continuously struck by the gas which enters the compressor at a pressure of about 5 atmospheres,may break and so is no longer directed toward the muffler hole.
A further drawback of this solution is the considerable vibration to which the little plate is subjected and thus an increase of noise.